A homicide suspect watching the Charlotte Bobcats from a VIP suite in 2010 found himself surrounded when undercover officers intruded and arrested him for a shooting in New York City.
In another case, Charlotte-Mecklenburg police in 2012 tracked the suspected “ski mask rapist” to a small town near Myrtle Beach some 30 years after he sexually assaulted three women.
And this past summer, CMPD officers arrested the ex-boyfriend of Bianca Tanner and charged him with first-degree murder in the death of the second-grade teacher from Greensboro.
Documents unsealed last week show that Charlotte-Mecklenburg police turned to secret cellphone surveillance to make the three arrests and to investigate other high-profile cases. The device they often used, commonly called a StingRay, mimics a cellphone tower and helps authorities pinpoint the location of phones.
But such tracking is under intense scrutiny after the newly released records raised questions about whether police and prosecutors properly disclosed how they pursued suspects. Experts also question whether documents police use to seek permission from the court are too vague.
Chief Rodney Monroe and District Attorney Andrew Murray told the Observer their agencies are reviewing whether authorities turned over enough information to defendants and their attorneys, as required by law.
Police obtained permission from local judges to conduct cellphone tracking, but legal experts who viewed the records said it is uncertain whether some of the surveillance was constitutional.
They said they had doubts about whether judges fully understood how officers gathered information in the investigations. The court orders that authorize the surveillance do not mention StingRays or explain that the device captures cellphone data from both criminal suspects and innocent people.
“The U.S. Supreme Court and the state Supreme Court have not ruled on this,” said Jeffrey Welty, a criminal law professor at the UNC School of Government. “Everybody is working in an environment where there is some legal uncertainty. Nobody really knows what level of protection is afforded someone’s cellphone.”
A judge recently rejected an application from CMPD to conduct the cellphone surveillance. It was a first for police. The visiting judge seemed to have read an Observer report detailing how officers discreetly collect cellphone data, Monroe said.
In his first public comments on the issue, Murray said his office is reviewing hundreds of cases since 2010 to help maintain public confidence in the local criminal justice system.
“This has caused a lot of questions about the process,” Murray said. “We are going to take a hard look at the policy.”
Records raise questions
Authorities took action after The Charlotte Observer and its news partner, WBTV, filed a petition in Superior Court to unseal records related to CMPD cellphone tracking dating back to 2006. Mecklenburg Senior Resident Judge Richard Boner last week ordered the documents unsealed.
Records show CMPD sought court permission to use cellphone surveillance more than 500 times since 2010, or about twice a week.
Officials acknowledged that they failed to keep records of court orders from 2006, when the city first purchased a StingRay, until 2010. The error means there is no way for the public to see how often police used the technology or if there was any judicial oversight during those four years.
All told, the unsealing of the documents represents one of the largest disclosures to date about a police department’s use of a StingRay. Law enforcement agencies and the federal government have battled to hide information about the device from the public, saying they don’t want suspects to learn how to avoid detection.
StingRays, known generically as cell site simulators, can provide officers with serial numbers, location and other information about nearby phones, laptop computers and tablets that connect to a cellular network.
Privacy groups have fought for years to learn how law enforcement uses the technology. They question whether it violates the Constitution’s protections against unreasonable search and seizure.
Nicole Hardin, a Florida attorney who consults defense attorneys about StingRays, reviewed copies of the CMPD court orders and applications.
She said the orders compel mobile carriers to provide CMPD with the electronic serial number assigned to each phone. Police can learn a suspect’s general location because the orders require carriers to tell officers which cellphone tower is receiving signals from the phone with the electronic serial number.
At that point, Hardin said, investigators can take a StingRay to a specific area and pinpoint a phone’s location.
“They drive around in a tighter and tighter circle as the signal gets stronger,” she said.
Hardin said it is troubling that the applications filed by CMPD for cellphone surveillance are so vague that it is nearly impossible for anyone without specialized knowledge to tell when officers plan to use a cell site simulator during an investigation.
“It raises a lot of red flags,” Hardin said. “People doing things above board don’t need to hide.”
Monroe said that officers don’t always use cell site simulators, even though they have permission to do so. He said the court orders permit officers to obtain a range of cellphone information, and they actually only used simulators in less than half the cases.
Hanni Fakhoury, attorney for the Electronic Frontier Foundation, a privacy group, noted the court orders do not mention StingRays or explain that the device captures cellphone data from both criminal suspects and innocent people.
“The failure to mention StingRay meant the judge had no opportunity to place some limitations on the acquisition or retention of innocent people’s data,” Fakhoury said.
In his first interview about cellphone surveillance, Monroe told the Observer officers are striking the right balance between public safety and protecting constitutional rights.
Officers cannot listen to phone conversations and do not store data collected from innocent people. The equipment CMPD owns does not have the ability to capture voice content, Monroe said.
At the same time, he said, the cell site simulator has been an effective tool that helps get violent felons off the street faster. Monroe said he hopes the unsealing of the records will show why the surveillance is needed.
He disagrees with suggestions that CMPD failed to turn over evidence prosecutors are obligated to share with defendants and their attorneys. By law, defendants have the right to inspect evidence the prosecution has compiled through the legal procedure of discovery, which is meant to ensure due process.
Typically, the district attorney’s office obtains information about each case from officers and shares it with defense attorneys.
CMPD gave prosecutors court records related to cellphone surveillance in some cases, Monroe said.
Other times, he said, officers did not provide documents because the department believed it was not required under the law. In those cases, he said, the use of cellphone tracking was not central to charges against a suspect.
North Carolina has one of the broadest discovery statues in the country, forcing law enforcement to disclose nearly all information, local defense attorneys say.
But in most cases, CMPD cellphone tracking was used to locate suspects who already had been charged with crimes, Monroe said. The tracking was used not to build a case but to find suspects and bring them into custody. That means the government had no duty to share those records with defense attorneys, he said.
Monroe said the defense is only entitled to documents pertaining to the charges and not those related to how police made an arrest.
Monroe conceded that defense attorneys and others may interpret discovery laws differently but said he is not worried that criminals could challenge their convictions.
“I hopefully have enough faith in the court system to recognize blatant disregard versus a different interpetation,” Monroe said.
Monroe and District Attorney Murray said they discussed the topic on Friday. Murray said he agreed with Monroe that police and prosecutors aren’t required to divulge how police arrested a suspect.
But local defense attorneys, civil liberties advocates and Judge Boner have said they believe defendants should be made of aware of the cellphone surveillance.
Charlotte defense lawyer Noelle Tin said he is relieved the district attorney’s office is checking whether enough information was shared in past cases.
“It is a good and prudent decision,” Tin said. “I’m glad they’re doing it. It’s the right thing to do.”
‘The letter of the law’
If the district attorney’s office staffers find evidence that should have been shared, officials have said they will contact the defendants and their attorneys. Criminals could possibly petition the courts to set aside convictions.
Murray said his office followed “the letter of the law” and turned over all the information it had.
Prosecutors saw the once-sealed cellphone surveillance records for the first time this week. “We can’t provide what we weren’t given,” Murray said.
Because it appears the tracking mostly involved locating suspects who had already been charged, Murray said he isn’t particularly worried that convictions will be overturned.
After reviewing the records, Murray said prosecutors and lawyers for CMPD will try to determine whether they need to institute procedures for exchanging cellphone tracking information. Both Murray and Monroe said the issue has not surfaced before.
Knowledge of technology
Privacy groups say a lack of transparency about police cellphone tracking has prevented meaningful judicial oversight.
Some judges are not knowledgeable about technology, and police give them little or no information about StingRays when seeking orders.
Welty, the UNC professor, said this puts officers at a distinct advantage when they try to persuade judges to give permission. The police officer typically has received training and has expertise about StingRays and other equipment; judges do not.
Judge Boner, who has said he regularly authorized CMPD cellphone tracking, said that he did not know until recently that StingRays collect phone data from suspects and innocent people alike.
“I didn’t know what you called” the device, Boner said. “It was not important for me to know the manufacturer. I just want to know why (police) wanted (the information). The whole purpose is why do you want it.”
Reporter Ames Alexander, Database editor Gavin Off, and Researcher Maria David contributed to this story.